Not sure if this is an common knowledge... I just read a review of the new Mk2 teles and it appears that Canon has removed the protective glass that used to be first in line for abuse and scratches. So now when you get dirt and scratches it's on the real thing (optical lens).
It will cost a wee bit more to replace than the plain glass Still shaved a few grammes of the weight tought
It was discussed at the time they were announced.
It removes weight from where it matters the most: the front of the lens, therefore affecting (favorably) the center of gravity, making them feel lighter than they are.
WebDog wrote:
Not sure if this is an common knowledge... I just read a review of the new Mk2 teles and it appears that Canon has removed the protective glass that used to be first in line for abuse and scratches. So now when you get dirt and scratches it's on the real thing (optical lens).
It will cost a wee bit more to replace than the plain glass Still shaved a few grammes of the weight tought
First every lens is "optical" even the glass element is a part of the optical formula. The front element on MKII lenses has a tough hydrophobic coating, it is tougher than the old glass element.
With the front hood which is quite deep attached it is extremely unlikely to get dirt or scratches on the front element anyway.
speedmaster20d wrote:
First every lens is "optical" even the glass element is a part of the optical formula. The front element on MKII lenses has a tough hydrophobic coating, it is tougher than the old glass element.
With the front hood which is quite deep attached it is extremely unlikely to get dirt or scratches on the front element anyway.
I'm scared to touch mine, what do you suggest for cleaning the new front elements with the hydrophobic coating?
I use a blower usually. if there are spots l use standard lens cloth. These lenses are made tough and can take a lot of punishment I wouldn't worry too much.
artsupreme wrote:
I'm scared to touch mine, what do you suggest for cleaning the new front elements with the hydrophobic coating?
(1) Rocket blower after every lens use, and before any other cleaning method.
(2) Canon micro fibre lens cloth if you can get those......CPS usually gives them out for free.
If not, Leica lenscloths are fairly good.
(3) Your regular optician's lens cleaning fluid for easy and light cleaning jobs.
(4) ROR for tougher spots.
(5) Broad tipped Lenspen for those times when even ROR would leave smears or a residue film.
Make absolutely sure the Lenspen tip is clean and free of any hard particulates.
Do not use recycled $7 lenspens on a $11,000 lens.
PetKal wrote:
(1) Rocket blower after every lens use, and before any other cleaning method.
(2) Canon micro fibre lens cloth if you can get those......CPS usually gives them out for free.
If not, Leica lenscloths are fairly good.
(3) Your regular optician's lens cleaning fluid for easy and light cleaning jobs.
(4) ROR for tougher spots.
(5) Broad tipped Lenspen for those times when even ROR would leave smears or a residue film.
Make absolutely sure the Lenspen tip is clean and free of any hard particulates.
Do not use recycled $7 lenspens on a $11,000 lens.
Thanks, sounds like I'll treat it just like the little 200/2 and 300/2.8IS
Still shaved a few grammes of the weight tought 
